All preparations containing salicylic acid and derivatives are classified in N02BA - Salicylic acid and derivatives, as it is difficult to differentiate between use of salicylates in rheumatic conditions and other therapeutic uses.

Exception: Salicylates in combination with corticosteroids are classified in M01B.

Combinations of antiinflammatory/antirheumatic agents (e.g. corticosteroids) are classified in M01B.

Combinations with muscle relaxants are classified in M03B.

Combinations with antibacterials are classified in J01.

Antiinflammatory or antirheumatic agents in combination with opioids are classified in N02AJ - Opioids in combination with non-opioid analgesics.

Combined cold preparations with therapeutic levels of antiinflammatory agents are classified in this group at separate 5th levels by using the 50-series.

Combinations with drugs classified in A02B (e.g. esomeprazole) are classified in M01A using the 50-series.

The DDDs are based on the treatment of rheumatoid arthritis, except for the coxibs (M01AH).